1. Field of the Invention
The present invention relates generally to material extruding apparatus and, more particularly, to sheeting extruders adapted to form pliant materials such as edible doughs into thin, continuous sheets.
2. Discussion of the Prior Art
Various types of sheeting apparatus for extruding pliant materials have been suggested. Typically, these devices embody one or more sets of cooperating rollers between which the material is passed to form it into thin sheets. Apparatus of this character has several inherent drawbacks. In the first place, the roller assemblies are generally quite expensive and are easily damaged. Additionally, certain types of materials, as for example, edible corn or wheat flour doughs, tend to adhere to the rollers and tenaciously resist separation therefrom, after the material has been sheeted or extruded. When these types of materials are being worked, therefore, the rollers must be specifically treated and mechanical means provided for separating the extruded materials from the rollers. Such expedients are often costly and frequently fail to perform in a reliable fashion. For example, the common technique used to separate the extruded material from the rollers is to position the small diameter wire in close proximity with the surface of the rollers in such a manner that the wire will urge separation of the material by a wedging action. When a fragile material is being extruded, however, the use of these stripper wires often tears the material or otherwise damages it. When this happens, the apparatus must be immediately shut down so that the damaged material can be cleared. Otherwise, a clogging of the machine will result. This is time consuming, costly, and highly undesirable.
The apparatus of the present invention successfully overcomes most of the drawbacks of the prior art devices. Since, in the apparatus of the present invention, extrusion is not accomplished in the standard manner using cooperating rollers, the problems inherent in separating the material from the rollers is avoided. As will be better understood from the description which follows, in the apparatus of the present invention, the pliant material is extruded in a highly novel manner through the cooperative interaction of a multi-sided rotor mechanism and a reciprocating bladelike barrier member.
Although the apparatus of the present invention can successfully be used to extrude various materials, it is particularly useful in sheeting edible doughs of the types used in preparing various food items. For example, the apparatus is particularly well suited for sheeting masa dough which is used in the production of tortillas. The masa dough is quite fragile and has a tendancy to tenaciously adhere to rollers of the type used in prior art sheeting devices. Since extrusion rollers are not used in the apparatus of the present invention, the problems of separating the fragile material from the rollers without tearing or otherwise damaging it, are completely avoided.